C# 

using Microsoft.AspNetCore.Mvc;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebAppMVC.Controllers
{
    public class FirstController : Controller
    {

        // 控制器代码 



        public IActionResult Index()
        {
            // MVC开发传值  
            { 
            // 业务逻辑 计算 
            // 结果要展示给view
            // 

            base.ViewBag.User1 = "张三";
            base.ViewData["User2"] = "李四";
            base.TempData["User3"] = "王五";
            base.ViewBag.User4 = "MVC传值的成功实现！";



                //base.HttpContext.Session["User4"] = "赵六";
                object model = "Richard";


            }


            return View();
        }
    }
}

   CSHTML 

@{
    ViewData["Title"] = "Home Page";
}

<div class="text-center">
    <h1 class="display-4">Welcome</h1>
    <p>Learn about <a href="https://docs.microsoft.com/aspnet/core">building Web apps with ASP.NET Core</a>.</p>
</div>


 <h2>this is index  </h2>
@model string
<h3>ViewBag.User1-@base.ViewBag.User1</h3>
<h3>ViewData.User2-@base.ViewData["User2"]</h3>
<h3>TempData.User3-@base.TempData["User3"]</h3>
<h3>ViewBag.User1-@base.ViewBag.User4</h3>
<h3>ViewBag.User1-@base.ViewBag.User1</h3>

效果